Estimation of the Lime Requirement of Selected soils in some Ecological Zones of Nigeria

Abstract

Liming is necessary for sustainable crop production on acid sands. A pot experiment was conducted in year 2004 on 'Acid-sands' of Akwa, Kugbo from the derived savannah and kufo from Southern Guinea Savannah agroecological Zones of Nigeria to estimate their lime requirements. The treatment consisted of three soils (Akwa, Kugbo and Akufo) and two lime sources (calcium carbonate and hydrated lime) applied at the rates of 0,2,4 and 6 ton ha-1 to the soils. The experiment was laid out in split plot design replicated three times. Soil pH was determined potentiometrically on the soil sub-samples at 4,6,8 WAL (Weeks after liming ) in 0.01M CaCI2 at solution ratio of 1:2. Regardless of lime sources, at least liming up to 2 tons ha-1 was necessary to raise soil from 6.0 – 6.5 at 6-8 weeks after liming (WAL). Benefits to liming with CaC03 may never be obtained at 4 WAL unless liming rate is increased to 4 ton ha-1 lime for Awka soil and 6 ton ha-1 for Akufo and Kugbo soils respectively. In the case of liming with hydrated lime, even 6 ton ha-1 lime will hardly give appreciable benefit with respect to soil fertility improvement, since the reference pH of 6-65 could not be attained. Lime of carbonate source seems to be a better choice than hydrated lime on this note. Further studies should however be carried out to investigate accrued benefits to crops due to liming these acid sands.